Using time-lapse photographic techniques we have identified three types of contractions in mouse submandibular gland rudiments in organotypic culture. The first and second types caused central and peripheral portions of the gland to contract synchronously. The third type caused the gland to contract asynchronously. Each type of contraction was given a functional name. The first type, which had a latency period that ranged from 30 minutes to 6 hours and appeared to purge the ducts and acini of their contents, is called voiding contraction. The second type, which had a latency period that ranged from 4 to 60 minutes and appeared to force the contents of distal tubules toward main ducts, is called priming contraction. The third type, which had a latency period that ranged from 5 to 14 minutes and appeared to whip acini randomly in a twitching manner, is called churning contraction. A preliminary film of these contractions will be presented at the 28th Annual Meeting of the Tissue Culture Association at New Orleans in June, 1977. Subsequently, a documented film of contractions in mouse submandibular gland, as revealed by time-lapse photography will be completed.